Read Oreilly.Hadoop.The.Definitive.Guide book. It points out the changes in new and old api.
On Thu, Feb 3, 2011 at 3:53 AM, Christian Kunz <[email protected]> wrote: > I don't know of a transition guide, but I found a tutorial based on the new > api: > > http://hadoop.apache.org/mapreduce/docs/current/mapred_tutorial.html > > I did not use it, but it might be useful. > > BTW, you could use the > > @Override > > annotation when overriding any method to let the compiler detect issues > like yours. > > -Christian > > On Feb 2, 2011, at 2:06 PM, Marco Didonna wrote: > > > On 02/02/2011 10:23 PM, Christian Kunz wrote: > >> Without seeing the source code of the reduce method of the > InvIndexReduce class > >> my best guess would be that the signature is incorrect. I saw this > happen when migrating from old to new api: > >> > >> protected void reduce(KEYIN key, Iterable<VALUEIN> values, Context > context) > >> > >> (Iterable, not Iterator as in the old api) > >> > >> -Christian > >> > > > > My God you're right...are you a sensitive or what :) :)? I am pretty new > > to Hadoop and I have studied the Tom White's book which is based on the > > old api (too bad)...I find quite difficult the migration to the new > > api...Is there a transition guide? > > > > Thank you very very much...I was going to call an exorcist since there > > was no warning, no error whatsoever... > > > > Marco > > > >
